Gaming journalist.It certainly has changed a lot from playing baseball in the MLB.
Well, that one at least is relatively easy to achieve. (This is just general advice so ignore if it's not relevant to you.)
Just start blogging about games, hone your skills and practice your writing. When your blog's been going 6 months to a year, start actively promoting it by leaving well-written, on-topic comments on "professional" (or widely-read) blogs where your profile information links back to your own blog. Regularly write to the letters pages of magazines - it's a great way to get noticed if your letters get printed - but again keep the focus on the subject in hand rather than just self-promotion, which is tiresome. Respond to other readers' comments and "get chatting" with the other folks who hang out at the blog/website/forum. Editors soon notice who the regulars are. Get a few business cards printed up with your blog/contact details. Go along to e.g. PAX, Eurogamer Expo, etc. and get chatting with everyone - the people on the stalls, the people milling around - and if someone seems "useful", give them a card. Use social networks, particularly Twitter (which is less formal/intrusive than Facebook).
Basically, after a while of doing that (a year or two - but remember, this is all time you're practicing and improving your writing), people will start to ask you to contribute to whatever they're doing. Be warned: most of it will be unpaid, and that which is paid will be very poorly paid. Journalists - even editors - do not earn much money, and most magazines have only a very few staff writers compared to many ad-hoc contributors (freelancers). You are far more likely to be someone with a full-time job who writes gaming articles on the side than you are to be a full-time game critic. Also, companies are cutting back on freebies and you are far more likely to be invited to somewhere to play the game on-site than to be given a free copy of the game.
Well, that's how to get
into doing it, which is the first of your problems. Just watch the '15Peter20' episode of Nathan Barley to see the reality of what it's like when you get there!